Full conjugated multilayer thin films fabricated by the alternate adsor ption of partially doped polyaniline (PANI) as a polycation and water-soluble p o ly(4-carboxyphenyl)acetylene (PA) as a polyanion were used as nanoreactors to s t udy the in situ preparation of PbS nanoparticles.First,the self-assembled mu ltilayers were immersed in a 1 mol/L NaOH solution to fabricate a controlled con tent of free carboxylic acid binding groups.Chemical reaction within the polyme r film was initiated by absorbing Pb 2+ from a 0 4 mol/L aqueous solutio n of Pb(Ac) 2 and followed by exposing the film to H 2S gas.UV-Vis absorp tion studies re veal that the absorption spectral profiles of the films are dependent on the dip ping time of the film in the Pb(Ac) 2 solution.AFM and TEM microscopic examina tions o f the films reveal that PbS crystals with rhomboid structures are formed in the films.The particles of narrow size distribution stand vertically on the fil m plane.Due to being doped by PbS,the photoelectric conversion property of ultra-thin composite films,which can be measured with a conventional three-e lectrod e photoelectrochemical cell using 0 5 mol/L KCl solution as the supporting elec tr olyte,is improved obviously.The results show that the value of the photocurren t for an 8\|layer film is 3 times higher than that of the original film.
